The correct answer is:
Gorbachev
Explanation:
1. Glasnost and Perestroika were policies introduced by Mikhail Gorbachev in the Soviet Union in the 1980s.
2. Glasnost refers to the policy of increased openness and transparency in government and media.
3. Perestroika refers to the restructuring of the Soviet political and economic system.
4. These policies played a significant role in the eventual fall of the Berlin Wall in 1989, which symbolized the end of the Cold War and the beginning of the reunification of Germany.
5. Stalin, Reagan, and Nixon were not directly associated with Glasnost, Perestroika, or the fall of the Berlin Wall.
